A terminal device that communicates with a base station apparatus includes a transmission unit that transmits a channel and/or a signal based on a maximum output power in a first cell group in a certain subframe. In a case where information relating to uplink transmission in the second cell group is recognized, a residual power is allocated based on a priority level of a type of uplink transmission. The residual power is given by subtracting a power that is determined based on uplink transmission in the first cell group and a power that is determined based on the uplink transmission in the second cell group from a sum of maximum output powers of the terminal device. The maximum output power is a sum of the power that is determined based on the uplink transmission in the first cell group and a power that is allocated to the first cell group, of the residual power.